Joel Edgerton, the Australian actor currently wowing them on the big screen as Tom Buchanan in 'The Great Gatsby', has just closed a deal to star alongside Johnny Depp in the crime thriller Black Mass, which tells the story of the difficult alliance between the FBI and notorious Boston criminal Whitey Bulger.

Bulger headed the FBI’s Ten Most Wanted List for a decade before he was put behind bars.

In Boston it was felt Bulger could never have evaded justice so long without the help of John Connolly, the FBI agent and childhood pal of Bulger and his brother.

Connolly's task was to take down the Italian mob and Bulger helped him, consolidating his own position as Boston's crime kingpin by eliminating his competition with his Winter Hill gang.

According to Deadline Edgerton will play Connolly, who was first praised and then eventually convicted of racketeering and obstruction of justice for aiding Bulger, who is currently in a Massachusetts state prison for second-degree murder. For decades Bulger was a ruthless kingpin whose reign of terror kept the city in fear.

Its a terrific part for the young Australian as it will allow him to play a law enforcement officer with conflicted loyalties.

The film's title comes from the 2001 Dick Lehr/Gerald O’Neill New York Times bestseller 'Black Mass: The True Story Of An Unholy Alliance Between The FBI And The Irish Mob.'

The plot received the third act it needed when Bulger was captured in California in summer 2011, after years on the lam.